System of electric-motor control.



No. 892,421. PATENTEDUULY v, 1908.

F. W. HARRIS. I SYSTEM OF ELECTRIC MOTOR CONTROL.

APPLICATION FILED $EPT. 5.1905.

FORD W. HARRIS, OF WILKINSBURG,

iitllil.

PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELEO SYSTEM OI ELEOTRIG-MOTOR GON'DROL.

Application filed September 5, 1905.

To all whom it may concern:

Be it known that 1, Form W. Halters, a citizen of the Uniter tatates, and a resident of W'ilkinsburg, in the have invented a new and useful improvement in Systems of Electricl\lotor Control, of which the following is a specification.

My invention relates to systems of electric motor control and particularly to systems which are adapted for starting relatively large motors.

The object of my invention is to provide a system for the )urpose setforth, that shall embody a set succcssively-closed switches of simple arrangement and construction; that shall be eil'ective in operation and that shall automatically open a main circuit interrupting device ii the switches oi the set are closed in other than the regular predetermined order. A

When relatively large electric motors are started by gradually reducing the resistance in series therewith it is desirable to sheet this result by means of: a plurality ol' switches which are closed in a predetermined order and which may be readily adapted for carrying and interrupting large currents without damage from arcing.

excessive heating or in the prior art it has been usual to 1nechan1cally interlock switches of this nature to insure their closure in a predetermined sequence, but inasmuch such interlocking means might be overcome by the application of" suilicient mechanical force, it was possible to close the switches in sucl order to so rcdiu'c the resistance that excessive currents would be supplied to the motor.

' The arrangement oi my invention does not prevent the closing otthe switches in any order or combination, but provides means for automatically interrupting the motor circuit iithey are closed in other than a prodctcrnihml, suitable order.

'lhe single iiguro of the accompanying drawing is a diagrammatic view ol my invention as applied to a single motor that is operated in one direction only. 1 desire it to be understood, however, that in y invention may he applied to a motor which is adapted for running in eitherdirection and that it may be otherwise modified as to number and i'nngcmcnt ol parts as well as in its applicalion, il' desired.

ltcl'crring to the di'awii'ig, electrical energy S ec'ificationol Letters Patent.

is supplied from Patented July '7, 1908.

Serial N0. 277,193-

a line terminal 1 through a main line circuit-breaker 2 to a motor 3,

Which is provided with a suitable starting 1 l county of Allegheny and State of Pennsylvania,

device 4, that regulates the amount of resistance which is connected in series with the 60 motor. The circuitbreaker 2 is arranged in the usual manner to entirey disconnect the motor ruin the supply line and is provided with an overload release magnet which erves to trip the breaker and open the circuit when the current supplied. to the motor exceeds a predetermined value.

The starting device 4 comprises a plurality of switches 6, 7, 8, 9, and 11 which may be so arranged and equipped as to be closed 70 e. her manually or otherwise and which may be provided with interlock relay switches 12, 13, 14, 15, 16 and 1'7. The system may also include a holding switch 18, which serves to prevent an attendant from leaving the start- 75 ing device before all the switches are closed; Each of the switches 6, 7, 8, 9, 10 and 11 is provided with a retaining coil 19 which serves to hold its switch in closed position after it is moved to such position i The interlock relay switches 12, 13, 16 and 17 are so connected. however, that the main motor circuit through 14, 15, and arranged, circuit and the holding coils 19 are interru ted by a circuit breaker 20, in case t e 35 switches are closed in other than a predeterinined order. i

in starting the motor 3, the switch 18 is first moved to its closed osition. The cir cult-breaker 20 is then c osed, pletes a circuit from the line terminal 1 through the contact, members 21 of the circuit-breal er 2 and its overload coil 5, field magnet winding 22 and armature 23 of the motor 3, breaker 20 and contact members 25 of the circuit-breaker 2 to an opposite line terminal 26.

The circuit-breaker 2-0 is normally held in its closed position by a holding coil 27, a cir- 100 cuit being completed, when the switches 6, 7 8, 8'), l0 and 11 are open and the switch 18 is closed, from the positive line terminal 1 through a conductor 28, switch 18, the con-- tact nicn'lbcis 254 and 36 and 37 and 3S oi the'respeclive relay switches 17, 16, 15, 14 and 13 and through conductor 39, coil 27 of the circuitbrcalrer 20 and the contact inembersoi circult-breakers 20 and 2 to the line terminal 26. 110

y the operator.

which coma series resistance 24, the circuit- 29 and 30, 31 and 32, 33 and 3 l'ering with the circuit through the holding m ouuily illl m :loscd pom 2 eeegle i As the switches 6, 8, 9 and 10 are suc- Sp cific illustration and description of cessively closed, resistances 40, 41,- 42, 4:3 prctc cmhodimcnt oi my invention are and 4ft are succe sivcly connected in mnlti-- not to he so constru d to exclude equivaple wlth the resistance 4 a 1 9 Switch lent means for cllcc'tinq substzmtially the 5 ll closed the conductor l6 is connected nre ult. i

d rectly to the conductor 47, thereby eho'rt- 1 claim :18 m" invention: clrcuitmg ell the rcsistsmces. Since each 1. In combixiationwith {1}! gicfl switch and its correspond ngresistanceisih- {t ph t of hidecciidmtiv mo .2 eluded between the conductors and 47, switches in sziid circuit; and ichns for auto- 10 the latter of which 1s connected to the cirlv l)I inc said circuit noon the elo Quit-breaker 20, it is obvious that the cir- 'ilclios out r" u 1, t, cuit-breakcr 20 must be closed next after the closing of the switcl'i 18. After the circuitbreakcr 20 has been closed, the switch 15; hechit, it nlnrnlitv oi mguiu 15 ing held in closed position, the switch ti may switches lDllOT'B'iOI and mums be closed, thereby connectin the resistance ally opening the ircuit when 40 in multiple with the resistance are: closed in. other than at inedctermiiied If any one Ol the Swit hes 7, 3,- 9, 10 (mil order, of it controlling switch tlmt must be 11 is closed While th wit h 6 is pen, h mzmnullv held in its clhscd nosiiinii unti said 20 aforesaid circuit through holding coil 27 oi switches iil'l) all closed.

the circuit-breaker 20 is interrupted and the 3}. in coinbilizilltm ith a circuit breaker is autonmticelly opened, After the switch 6 is closed, liowcvcr, n cir-- unit is completed from the torminzrl 3? r' the relay switch 13 through contact members l 8 and 49 of the relay switch l2 so ilml the suitchcs' Si} switch 7 ma he closed without interruptin the circuit through the retaining coil The closing oi the switch '7 completcs i: I it. he cuit from the contact member 33 of thc ui w, lu,;-;

switch 14 through contact members-50 and switches at or, and clcciiom grieth; 51 of thc rehty switch 13, which are un- 111011 for holding .chcs iii closhd onnectcd to the contact nicmbcr if, so thm he ition, ol 2! controziii 'llyl dh switch 8 may now be closed without ii craid l h o 111mm i m- Us it,

I who to who t l coil. The relay swilchcs l4, it; and i? said iimin swit are similarly and respe tively provided with The com! contact mcmbcrs 52- 5:3, Mia}? m-cl and 58---5th which are connoctcd town end it only when the corrcspondingg main. swnc nniount o? are closed. The connections through the lay switches l4, 15, 1i) and if, wl: readily understood lrom the l-lcscription ol the circuits through the switch 13, arc soc that the circnit-breaker 2!) will open if t switches 55, 7, 8, .7, l0 and H are ciosnd in other than the order named.

\Vhcn the switch ll is closed in, circuit is cl :11: completed l'rom conductor through the in each;

(I c b 4 X \l J! contact mcmbcrs 5S and 5K) ol the relay andmozmsloron switch 17 so that the switch 1% may he aid switches are i opened. without nll'ccting the circuits already completed.

A grudtml and suitable rodnction oi the cuit, rind it pluralitresistance in series with the motor in his main switches thcrc i,

started is oll'cctcd hy the means heroin sct malicnlly opt-hing the circuit l'orlh and tho ntlninmcnl ollnil spccd conaliswiichcs :irc cl 'l in othcr ll:

tions is insured bccuusc the switch 325 must mined orde sum means compr be held in :1 closed position'hy the attendant l l{lilli"i l 60 until the res mice is slaort-circnilcd. in

llllw wary at rcsistnncc ol' rclntiyt' small c:

pm ily l'oi' con inuous sci-vice, mo be sz'il cly nliizcd l'or starting; the motor c it may be kept undo! the observation o'l c attend out during its entire period or of me l'or unlosaid '1 nrcnclcrcod tori by ;he cirt" ;,-lureh the-color, ind creams ior cit-tom;

ally opening the main circuit when said s *itches are closed non-sequentially, said means comprising a circuit-breaker having a retaining coil and a plurality of relay switches actuated by said main switches to determine the circuit connections for said vretaining coil, of a controlling switch that nuist be manually until the main switches are all closed.

9. 'The combination with an electric motor and a cii nit-interrupting device connected in series therewith, 0t starting means for said motor that comprises a plurality of manually-operated switcl'ies and means -l'or open: ing said circuit-interrupting device when the switches are closed in other than a prodetermined order.

10. The combination with a supply circuit, an electric motor, an interrupting device for said circuit, a plurality of starting resistances for said motor, and means for adjusting their circuit connections in 'a regular order, of means for actuating said interrupting device to break the supply ci 'cuit when the circuit connections of tlic resistances are adjusted irregularly.

11. In an electric circuit, the combination with a plurality of switches adapted "for closing in a predetermined order, of a circuitbrealrer and means for tripping the same .when any switch closed in other than its proper order.

'12-. The combination with an electric cir cult, and a plurality of switches there'lcr that are constructed and arranged to be closed in 'a predetermined sequence, of means for auto matically opening the main circuit with which said switches are connected whenever any switch is closed non-sequcntially.

13. The combination with a supply circuit, a dynamo-electric machine and. a starting resistance tliere'ior, of a plurality of switches for varying said resistance and means for automatically interrupting the supply circuit when any switch is closed non-sequentially.

14.. The combination with a main circuit and a variable resistance therefor, of a plu rality of switches adapted and arrang ml for progressively varying said resistance, and means for automatically opening the main circuit whenever any switch. is closed ncnsequentially.

15. The combination with a main circuit and an interrupting device therefor, of a rc-- sistancc, a' plurality of switches connected and. arranged for sequential operation. to progressively vary the ell'ective amount or said resistance and means for automatically tripping the circuit interrupter when any ;-:witch is closed non-sequentially.

it. In combination with an electric circuit, a plurality of independently inovable switches ii]. said circuit, an olectroenagnet ointly cmitrolled by said switches, and

held in closed position l l l l l l l l 1 cuit, a plurality el e.

means controlled by said electromiagnet 'for autoin aticallv breaking said circuit upon the ole ad switches out a predeterk or ruined order.

17. in c nibination with an electric cirin said circuit, a ire-voltage release dcx 'ce operatively connected to one oi said switches, and contacts controlled. by the other switches controlling said device.

ii-:1 in combination with an electric circuit, plurality of switchesin said circuit, a ire-voltage release device operatively connected to one of said vitclics, and means for decnergir/iing said do upon the closing of the other switches out of predetermined order.

19. In combination with an electric circuit, a plurality oi switrhes in said circuit, a Ire-voltage release device operativcly con nccted to one of said switches, and switchcontacts controlled by the other switches arranged to break the circuit of said device upon. the closing of said switches out of a predetermined order.

20. in combination with rheostat, a plurality ojl incchanically-imlcpendent switches controlling the resistance thereof, and means for automatically breaking the circuit cl said rheostat upon the closing of said switches out of prodetcrn'iined order.

21. in combination with a rheostat, a plurality oi nicchanically-mdcpendent switches controlling he resistance ll eof, an electro magnet ointly controlled i j said switches, and means controlled by magnet for auton'iatically breaking the circuit of said rhe0- stat.

in combination with a rheostat, a plurality oi inechanically-independent switches controlling the resistance theero'r', a no-voltags release device, and contacts controlled 0v said. switches and controlling said device. in combination. with a rheostat, a plucity of mocha-n. allyin.dependent switches ztrclling the thereof, a llO-VOlrelease device, contacts controlled b said switches andfarranged to break the rid device upon the closing of said switches out of predeh, mined order.

In con .lz'tion will an electric cirl? indspendently-niovablc said circuit, an electro-inagnet, inc-ans .cntrolled by said magnet for breaking c uit when. the magnet is deiincrgreed, con controlled by said switches for dcencrgizing s id magnet upon the closing oi said. switches out oi a predetermined order, *nd normally open switch in circuit with said niagnetand arranged to be short circuitcd by the closing of the last oi the first-Rained switches.

T i ion with electric cirof independontly-qnovable circuit, an electro-magnet, 

